Performance evaluation of biomass co-gasification with coal in entrained-flow gasifirer

In order to enhance the operation stability of biomass co-gasification in entrained flow gasifier, based on an equilibrium RGibbs reactor model, O2/fuel mass flow ratio maps of dry feed gasifier and slurry feed gasifier with oxygen as agent have been built and the performances of co-gasification have been evaluated. The basic conditions are (1) wood, straw and sludge are selected as three types of biomass; (2) 5% to 20% of coal is replaced by biomass in weight; (3) the biomass moisture content changes from 5% to 30% in weight. O2 mass flow ratio has been controlled to maintain the gasifier´s operation at 1350°C in different cases. The product gases compositions and LHV of gases change with the biomass replacing ratio and the biomass moisture content. The results show that co-gasification performances decrease more when the ratio of biomass replacing coal and the biomass moisture content increase simultaneously and it is necessary to modify O2/fuel mass flow ratio greatly to maintain the stable operation temperature.